Market Share And Switching Dynamics Between Etanercept And Its Biosimilar Product In Sweden And Germany: A Real-World Preliminary Analysis

OBJECTIVES: To describe the market share and switching dynamics between etanercept innovator (Etnl) and its biosimilar (EtnBS) indicated for rheumatic diseases, in Germany and Sweden. METHODS: Patients receiving rheumatologists' prescriptions for Etnl and EtnBS in November 2015-March 217 were retrospectively identified using the Swedish Prescription Registry (100% of retail biologic prescriptions) and the QuintilesIMS® German Longitudinal Prescriptions database (LRx, 60% of the German statutory health insurance market). In each country, the monthly proportion of patients on Etnl and EtnBS was recorded. In addition, the monthly proportion of naive patients and of those switching to EtnBS from prior Etnl or other biologic treatment were evaluated (12-month lookback period), along with the proportion of patients who switched back to Etnl or other biologies after starting EtnBS. RESULTS: Both in Germany and Sweden, the market share of Etnl constantly decreased and that of EtnBS constantly increased after EtnBS was launched. In the month of launch (Germany: February 2016; Sweden: April 2016), the proportion of patients who switched to EtnBS from any biologic treatment was -100% in Germany and only 22% in Sweden. In the most recent 6 months, this proportion ranged from 41% to 49% in Germany and from 61% to 72% in Sweden. In both countries there was a similar proportion of patients with prior Etnl who switched back to the original Etnl (10% in Germany and 11% in Sweden) or any biologic agents (14% in both countries) after only 75 (Germany) and 55 (Sweden) days of treatment with EtnBS. CONCLUSIONS: Despite the observed differences in market penetration, we found that both in Germany and Sweden there is a proportion of patients who switch back to the original biologic agent after being moved to EtnBS. Future studies should confirm these results and investigate the reasons for changing back to original biologies.